The present disclosure relates to an electronic circuit board, a laminated board, and a method of manufacturing the electronic circuit board.
Endoscopes have been widely used for various examinations in the medical field and the industrial field. Especially, medical endoscopes are widely used, because by insertion of an elongated and flexible insertion unit having a solid state imaging element provided at a distal end thereof into a body cavity of a subject, such as a patient, in-vivo images inside the subject are able to be acquired without incision of the subject, and further, curative treatment is able to be carried out by protrusion of a treatment tool from the distal end of the insertion unit, as necessary.
In an imaging device used in such an endoscope, generally: a light receiving surface of a CCD chip thereof is covered by cover glass; an inner lead of a TAB tape is connected to an electrode provided at an outer peripheral edge portion of the light receiving surface; and the CCD chip is connected to electronic components and an external information processing device (see, for example, Japanese Unexamined Patent Application, Publication No. H11-76152).
In recent years, the number of electronic components used in an imaging device has increased, but for reduction of burdens on subjects, decrease in diameters and decrease in lengths of distal ends of insertion units of endoscopes are demanded, and thus a technique for improving mounting density of electronic components has been desired.
As a technique for improving mounting density of electronic components, a technique of forming a recessed portion in a silicon board and mounting a mounted component in the recessed portion has been proposed (see, for example, Japanese Unexamined Patent Application, Publication No. 2002-151801).
Further, a technique of forming an opening in a metal core, blocking the opening by forming an insulating layer on at least one of principal surfaces of the metal core, and mounting an electronic component in the opening has been proposed (see, for example, Japanese Unexamined Patent Application, Publication No. 2013-141028).